Electrical Wiring Systems For Use In Roofing Applications

ABSTRACT

The present invention relates generally to electrical systems. The present invention relates more particularly to electrical wiring systems suitable for use in roofing applications. One aspect of the invention is a wiring system on a roof comprising a roof deck having a slope and one or more roofing elements disposed on the roof deck, the wiring system including one or more wires extending along the roof on top of the roofing elements; and a wire covering disposed over the one or more wires.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/015,121, filed Jan. 27, 2011, now U.S. Pat. No. 8,720,132, each ofwhich is hereby incorporated by reference in its entiretly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to electrical systems. Thepresent invention relates more particularly to electrical wiring systemssuitable for use in roofing applications.

2. Technical Background

The search for alternative sources of energy has been motivated by atleast two factors. First, fossil fuels have become increasinglyexpensive due to increasing scarcity and unrest in areas rich inpetroleum deposits. Second, there exists overwhelming concern about theeffects of the combustion of fossil fuels on the environment due tofactors such as air pollution (from NO_(x), hydrocarbons and ozone) andglobal warming (from CO₂). Moreover, the very discovery and exploitationof fossil fuels carries significant environmental risk. In recent years,research and development attention has focused on harvesting energy fromnatural environmental sources such as wind, flowing water, and the sun.Of the three, the sun appears to be the most widely useful energy sourceacross the continental United States; most locales get enough sunshineto make solar energy feasible.

Accordingly, there are now available components that convert lightenergy into electrical energy. Such photovoltaic elements are often madefrom semiconductor-type materials such as doped silicon in either singlecrystalline, polycrystalline, or amorphous form. The use of photovoltaicelements on roofs is becoming increasingly common, especially as deviceperformance has improved. They can be used to provide at least asignificant fraction of the electrical energy needed for a building'soverall function; or they can be used to power one or more particulardevices, such as exterior lighting systems.

Often perched on an existing roof in panel form, these photovoltaicelements can often be quite visible and generally not aestheticallypleasant. Moreover, the electrical cables used to interconnect thephotovoltaic elements can be another source of aesthetic dissonance.Nonetheless, to date, installations have appeared to have been motivatedby purely practical and functional considerations; there appears to havebeen little coordination between the appearance of the photovoltaicsystem and the roofing materials (e.g., tiles or shingles) and buildingsupon which they are mounted. Lack of aesthetic appeal is especiallyproblematic in residential buildings with non-horizontally pitchedroofs; people tend to put a much higher premium on the appearance oftheir homes than they do on the appearance of their commercialbuildings.

Accordingly, there remains a need for photovoltaic systems having morecontrollable and desirable aesthetics for use in roofing applicationswhile retaining sufficient efficiency in electrical power generation,and for aesthetically appropriate building elements for use withphotovoltaic systems.

SUMMARY OF THE INVENTION

One aspect of the invention is a wiring system on a roof including aroof deck having a pitch and one or more roofing elements disposed onthe roof deck, the wiring system including one or more wires extendingalong the roof on top of the roofing elements; and a wire coveringdisposed over the one or more wires.

Another aspect of the invention is a roof-mounted electrical systemelectrically coupled to a wiring system as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of a wiring system accordingto one embodiment of the invention;

FIG. 2 is a schematic top view of the wiring system depicted in FIG. 1.

FIG. 3 is a close-up cross-sectional view of the wiring system of FIGS.1 and 2;

FIG. 4 is a schematic cross-sectional view of a wiring system accordingto another embodiment of the invention;

FIG. 5 is a schematic cross-sectional view of a wiring system accordingto another embodiment of the invention;

FIG. 6A is a schematic cross-sectional view of another wiring systemaccording to another embodiment of the invention;

FIG. 6B is a schematic cross-sectional view of another wiring systemaccording to another embodiment of the invention;

FIG. 6C is a schematic cross-sectional view of another wiring systemaccording to another embodiment of the invention;

FIG. 6D is a schematic cross-sectional view of another wiring systemaccording to another embodiment of the invention;

FIG. 6E is a schematic cross-sectional view of another wiring systemaccording to another embodiment of the invention;

FIG. 6F is a schematic cross-sectional view of another wiring systemaccording to another embodiment of the invention;

FIG. 7 is a schematic cross-sectional view of a wiring system accordingto another embodiment of the invention;

FIG. 8 is a schematic cross-sectional view of a wiring system accordingto another embodiment of the invention;

FIG. 9 is a pair of schematic cross-sectional views of wiring systemsaccording to other embodiments of the invention;

FIG. 10 is a schematic side perspective view of a wiring systemaccording to another embodiment of the invention;

FIG. 11 is a schematic top view of the wiring system depicted in FIG.10;

FIG. 12 is a schematic cross-sectional view of a wiring system accordingto another embodiment of the invention;

FIG. 13 is a schematic perspective view of the roof-facing surface of aflexible wire cover according to one embodiment of the invention;

FIG. 14 is a schematic side perspective view of a wiring systemaccording to another embodiment of the invention;

FIG. 15 is a schematic top view of the wiring system depicted in FIG.14;

FIG. 16 is a schematic side perspective view of a wiring systemaccording to another embodiment of the invention;

FIG. 17 is a schematic top view of the wiring system depicted in FIG.16;

FIG. 18 is a schematic perspective view of a photovoltaic roofing systemin conjunction with a wiring system according to one embodiment of theinvention;

FIG. 19 is a schematic perspective view of a photovoltaic roofing systemin conjunction with a wiring system according to one embodiment of theinvention;

FIG. 20 is a schematic perspective view of an end of a top flashingsuitable for use in the photovoltaic roofing system of FIG. 19;

FIG. 21 is a schematic perspective view of a top flashing for use withthe wiring systems described herein is shown in in FIG. 21; and

FIG. 22 is a schematic perspective view of a photovoltaic systemaccording to another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the invention is a wiring system on a roof comprising aroof deck having a slope and one or more roofing elements disposed onthe roof deck, the wiring system including one or more wires extendingalong the roof on top of the roofing elements; and a wire coveringdisposed over the one or more wires.

One embodiment of the invention is shown in schematic cross-sectionalview in FIG. 1 and in top schematic view in FIG. 2. A wiring system 100is disposed on a roof 110. Roof 110 includes a roof deck 112 withroofing elements 114 disposed thereon, arranged in offset overlappingrows as is familiar to the person of skill in the art. Wiring system 100includes a wire 102 extending along the roof 110 on top of the roofingelements 114, and a wire covering 104 disposed over the wire 102. In theschematic top view of FIG. 2, wire 102 is shown in dotted line, as it isdisposed underneath the wire covering 104.

In certain embodiments of the invention, the wire covering has anup-roof end and a down-roof end, with the up-roof end of the wirecovering meeting the roof at a substantially horizontal or down-slopingangle. In the embodiment of FIGS. 1 and 2, the wire covering 104 has anup-roof end 106 and a down-roof end 108. Notably, the up-roof end of thewire covering meets the roof at a down-sloping angle. In thisembodiment, the up-roof end of the wire covering lays flat against theroof surface, and therefore has substantially the same slope as theroof. As used herein, the slope of the roof is generally determined asthe roof traverses from the ridge toward the eave. When determiningwhether the up-roof end of the wire covering meets the roof at adown-sloping angle, the thickness of the material of the wire coveringis discounted, unless that thickness is greater than half an inch. Insuch embodiments, snow, ice and water will not collect at the interfacebetween the roof and the wire covering, reducing the amount of moisturethat would work its way underneath the wire covering and to the wire.Similarly, debris will not tend to collect at the interface between theroof and the wire covering, reducing the need for people to climb uponto the roof to remove debris.

In certain embodiments of the invention, the wire covering forms noup-facing valleys having a substantially up-sloping down-roof end. Aclose-up cross-sectional view of wiring system 100 is shown in FIG. 3.In this example, wire covering 104 forms two up-facing valleys, 122 and126. Up-facing valley 122 has a down-roof end 124, and up-facing valley126 has a down-roof end 128. Notably, both down-roof ends 124 and 128slope down, with down-roof end 124 sloping down more than does down-roofend 128. As the person of skill in the art will appreciate, in otherembodiments, the down-roof end of an up-facing valley can besubstantially horizontal. In such embodiments, snow, ice and water willnot collect in the up-facing valley, reducing the chance ofwater-induced failure in the valley, and therefore the amount ofmoisture that would work its way underneath the wire covering and to thewire. Similarly, debris will not tend to collect at the interfacebetween the roof and the wire covering, reducing the need for people toclimb up onto the roof to remove debris.

In certain embodiments, the wire covering traverses a portion of theroof deck laterally, for example, as shown in FIGS. 1 and 2. The wirecovering can, for example, run substantially horizontally along aportion of the roof deck.

In the embodiment of FIG. 1, the roofing elements are asphalt roofingshingles. Of course, the person of skill will appreciate that othertypes of roofing elements can be used in practicing the presentinvention. Examples of roofing elements suitable for use in this aspectof the invention include shingles, tiles, panels, membranes and shakes,made from such materials as asphalt, polymeric materials, ceramicmaterials, stone, cementitious materials, and wood. In certainembodiments, a photovoltaic element is integrated with one or more ofthe roofing elements. The integration can be achieved in many ways, forexample as described in U.S. Patent Application Publications nos.2008/0271773, 2009/0000221, 2009/0000222, 2009/0133340, 2009/0133738,2009/0133740, 2009/0133739, 2009/0159118, 2009/0178350 and 2010/0146878,and in U.S. Provisional Patent Applications Ser. Nos.61/220,475 and61/232,739 each of which is hereby incorporated herein by reference inits entirety for all purposes. In certain embodiments, the roof has apitch of at least about 1″/12″, at least about 2″/12″, or even at leastabout 4″/12″, about 6″/12″, about 8″/12″ or about 12″/12″.

In certain embodiments, the wire covering is formed from a flexiblematerial. For example, in the embodiment shown in FIGS. 1-3, the wirecovering is formed from granule-coated asphalt shingle material. Ofcourse, the wire covering can be formed from other flexible materials,such as thin metal or polymer. In certain embodiments, the roofingelements are flexible roofing elements, such as asphalt shingles, andthe wire covering is made from the same material as the flexible roofingelements, such as granule-coated asphalt shingle material. In suchembodiments, the thermal behavior of the wire covering can substantiallymatch that of the flexible roofing elements, lessening the degree ofthermally-induced failure of the attachment therebetween in certainembodiments. Moreover, the appearance of the wire covering cansubstantially match that of the flexible roofing elements, making thecovering stand out less from the overall aesthetic of the roof.

Another embodiment of a wire covering formed from flexible material isshown in schematic cross-sectional view in FIG. 4. In wiring system 400,wire 402 is covered by wire covering 404. At its up-roof end 406, wirecovering 404 slopes downward, though less sharply than does the roof 410itself Wire covering 404 has no up-facing valleys.

In other embodiments, the wire covering is formed from a substantiallyrigid material. For example, in the wiring system 500 shown incross-sectional schematic view in FIG. 5, wire covering 504 is formedfrom a rigid material. In this embodiment, the up-roof end 506 of thewire covering meets the roof at a substantially horizontal angle. Wirecovering 504 also includes a portion 505 that lies between wire 502 androof 510, so that it substantially surrounds wire 502. The substantiallyrigid material can be, for example, sheet metal, or polymer (e.g.,molded, formed or extruded).

Other embodiments of wire coverings are shown in schematiccross-sectional view in FIG. 6. Notably, the angle the down-roof end ofthe wire covering makes with the roof can be adapted to provide adesired illusion of depth or thickness, particularly when a flexibleroofing element overlies it, as described below. Of course, the designscan be adapted to match different roof pitches, and to accommodatedifferent shingle exposures. In certain embodiments, the shape of thewire covering can be designed to make it less of a trip hazard when itis necessary to walk on the roof For example, in certain embodiments,the wire covering can form only acute angles with the roof (e.g., lessthan 60°, or less than 45°). In certain embodiments, the wire coveringcan extend less than about 2″, or even less than about 1″ from thesurface from the roof, as measured perpendicularly to the roof surface.

In certain embodiments, when the wire covering is not formed from thesame material as the roofing elements, it can be covered by the materialused to make the roofing elements (e.g., their top surfaces). Forexample, as shown in schematic cross-sectional view in FIG. 7. In FIG.7, wiring system 700 includes wiring 702 with wire covering 704 disposedthereon. Disposed on the wire covering is a layer of roofing material732, which substantially matches the roofing material of roofing element714. Thus, the roofing material 732 hides the wire covering and providesincreased aesthetic matching with the roofing element 714. In certainembodiments, the wire covering is formed from a rigid material. In suchembodiments, the wire covering can act to provide mechanical protectionfor the wiring, without contrasting sharply with the appearance of theroofing elements.

When material used to make the roofing elements (e.g., their topsurfaces) covers the wire coverings, it need not cover them entirely.For example, as shown in FIG. 8, wire covering 804 is disposed onroofing element 814, covering wire 802 disposed thereon. Disposed on thewire covering is a layer of roofing material 832. In this embodiment,the layer of roofing material covers the top face 806 of wire covering804, but not its lateral face 805. The lateral face can, for example,provide an appearance of thickness or shadow to the roof. In certainembodiments, the lateral face of the wire covering is printed orpatterned to provide a desired aesthetic effect. Of course, in certainembodiments of the invention, a wire covering is covered with materialused to make the roofing elements so that it is not exposed, as shown inFIG. 7.

In certain embodiments, the wiring is held by one more or wire holdingstructures, which is also disposed beneath the wire covering. Forexample, in the embodiment shown in schematic cross-sectional view inFIG. 9, a wire holding structure 922 a holds wire 902 a. Wire covering904 a is disposed over the wire, on top of the wire holding structure.The wire holding structure can also give shape to the overlying wirecovering, for example, to ensure that it does not collect water (e.g.,at the interface with the roof or in any up-facing valleys). Forexample, in FIG. 9, the wire holding structure 922 a is formed fromsubstantially rigid sheet metal, and provides the necessary shape to thewire covering such that it forms no up-facing valleys having anup-sloping down-roof end. Wire 902 a can be disposed by flexing thesubstantially rigid material of the wire holding structure 922 aslightly to widen the opening sufficiently to admit the wire.

In the embodiment of FIG. 9, the wire holding structure extends alongthe roof with the wire. Of course, as the person of skill in the artwill appreciate, wire holding structures can be provided in a number ofmanners, from the relatively simple to the relatively complex. The wireholding structures can be, for example, a plurality of hooks or clipsthat engage the wiring at multiple points along its length. In someembodiments, the wire holding structures can be formed from cooperatingpieces that act together to hold the wiring in place. For example, inthe embodiment shown in schematic cross-sectional view in the right halfof FIG. 9, wire holding structures 922 b and 924 b cooperate to holdwiring 902 b.

In certain embodiments, the wire covering itself can include wireholding structures on its roof-facing surface. For example, the wirecovering can include clips or hooks on its underside that engage thewiring at multiple points along its length.

In certain embodiments, at least the up-roof end of the wire covering iscovered by one or more of another roofing elements. For example, asphaltshingles are conventionally installed with their down-roof ends (e.g.,tab regions) laying flat against the roof. As shown in schematic sideview in FIG. 10 and schematic top view in FIG. 11, wire 1002 is disposedon roofing elements 1014, and covered by wire covering 1004. The up-roofend 1006 of wire covering 1004 is disposed beneath the down-roof end ofroofing element 1018. In such embodiments, the wiring can be betterprotected from moisture, as water will have a more difficult timeworking its way underneath the up-roof end of the wire covering.

In certain embodiments, the down-roof end of the wire covering issubstantially aligned with the down-roof end of the roofing elementsupon which it is disposed. For example, as shown in schematiccross-sectional view in FIG. 10, and in schematic top view in FIG. 11,the down-roof end 1008 of the wire covering 1004 is substantiallyaligned with the down-roof end 1019 of the roofing elements 1014 uponwhich it is disposed. Accordingly, the wire covering can blend in withthe pattern of the roofing elements, providing a more uniform-lookingroof surface.

In certain embodiments, the wire covering is formed from substantiallythe same material as the roofing elements, so that it matches theroofing elements. In other embodiments, the wire covering is made from adifferent material but not otherwise covered by roofing material. Incertain such embodiments, the wire covering is colored, patterned, orotherwise made to match or complement the appearance of the roofingelements. For example, in certain embodiments, a colored or patternedlayer can be provided on the wire covering.

In certain embodiments, the colored or patterned layer includes (eitherat one of its surfaces or within it) one or more colorants (e.g., dyesor pigments). The colored or patterned layer can also be patterned, inwhich one or more colors are varied over the area of the layer, forexample randomly or in some preselected arrangement. The color(s) andpattern(s) can be selected so that the layer has an appearance thatmatches, harmonizes with and/or complements a desired type of roofingmaterial, such as asphalt shingles of a given color and design. Thepattern of colorant can be, for example, uniform, or can be mottled inappearance. Ink jet printing, digital image printing, laser printing,gravure printing, roll printing, spraying, lithography, or any othersuitable printing or coating processes can be used to form the coloredor patterned layers for use in the present invention. In someembodiments, a high resolution graphic printing method is employed toreplicate the appearance of the surrounding roofing element, oralternatively, the appearance of other structures on the roof (e.g.,photovoltaic elements, either integrated with the roofing elements or asstand-alone modules). For example, the colored or patterned layer canapproximate the appearance of the roofing substrates (e.g.,granule-coated asphalt shingles).

A number of techniques can be used to provide the colored or patternedlayer. For example, U.S. Pat. Nos. 5,203,941, 5,284,693, 5,506,031 and5,662,977, each of which is hereby incorporated by reference herein inits entirety, disclose printed decorative layers disposed beneath aweatherable protective coating. U.S. Pat. No. 6,296,732, which is herebyincorporated herein by reference in its entirety, discloses an extrusionprocess for print and color coats suitable for imparting decorativeaspects to exterior products. U.S. Pat. No. 5,468,532, which is herebyincorporated herein by reference in its entirety, discloses a multilayerarticle having a graphic layer disposed between a substrate and aprotective layer. U.S. Pat. No. 6,180,228, which is hereby incorporatedherein by reference in its entirety, discloses a weatherable systemhaving an image layer with a protective layer laminated thereto. U.S.Pat. No. 6,753,065 and U.S. Patent Application Publication no.2007/0059493, each of which is hereby incorporated herein by referencein its entirety, disclose light-transmissive slip-resistant protectivelayers for protecting graphic-printed films. U.S. Pat. No. 7,138,173,which is hereby incorporated herein by reference in its entirety,discloses optical films that change color as a function of viewingangle. U.S. Patent Application Publication no. 2008/0006323, which ishereby incorporated herein by reference in its entirety, disclosesdecorative overlays positioned over photovoltaic elements that can beadapted for use in the present invention.

The wiring covering can be colored and/or patterned to resemble anatural roofing material such wood, slate or stone, or other manmadematerials such as ceramic or concrete. For example, in one embodiment ofthe invention, a graphic print reproducing a natural slate material(i.e., having shading and variegation emulating the natural texture andappearance of slate) is applied to a polymer film to provide the coloredor patterned layer. Of course, the wire covering could be colored and/orpatterned to have any desired pattern and/or color, and need not looklike traditional roofing materials. In certain embodiments of theinvention, the wire covering is colored and/or patterned to match theappearance of the roofing element upon which it is disposed.

In other embodiments, the wire covering can have a top-most layer thatis formed from material similar to that of the top-most layer of theroofing elements. For example, when the roofing elements aregranule-coated asphalt shingles, a top layer of granule-coated asphaltcan be formed on the wire covering.

In certain embodiments of the invention, the ΔE* between the wirecovering and the roofing element is less than 30, less than 20, or evenless than 10. As used herein L*, a* and b* are the color measurementsfor a given sample using the 1976 CIE color space. L*, a* and b* valuesare measured using a HunterLab Model Labscan XE spectrophotometer usinga 0° viewing angle, a 45° illumination angle, a 10° standard observer,and a D-65 illuminant. Lower L* values correspond to relatively darkertones. The strength in color space E* is defined asE*=(L*²+a*²+b*²)^(1/2). The total color difference ΔE* between twoarticles is defined as ΔE*=(ΔL*²+Δa*²+Δb*²)^(1/2), in which ΔL*, Δa* andΔb* are respectively the differences in L*, a* and b* for the twoarticles.

In certain embodiments, the outer surface of the wire covering is solarreflective. For example, the roofing granules disposed thereon can, forexample, be solar reflective granules. Solar-reflective granules can beused, for example, in areas of the wire covering that are to remainexposed to the atmosphere when it is disposed on the roof. In otherembodiments, a different solar reflective material is disposed on theoutside of the wire covering. The solar-reflective granules or materialcan operate to reflect a portion of the solar radiation (e.g., in theinfrared wavelengths) and thereby decrease the buildup of heat under thewire covering. The effective working temperatures of the wire coveringcan thereby be lowered, which can be advantageous in maintainingstructures under the wire covering at a desirably low temperature. Thesolar-reflective roofing granules or material can be disposed on thewire covering in an amount sufficient to provide the reflective areawith a solar reflectivity greater than about 0.25. In one embodiment ofthe invention, the solar-reflective roofing granules or material have asolar reflectivity greater than about 0.3, or even greater than about0.4. Solar reflectance can reduce the effective temperature of the wirecovering, which can improve the efficiency of power transfer by a cabledisposed thereunder, and can help to prevent thermal failure of thematerials used therein. Solar reflective materials are described in U.S.Patent Application Publication no. 2009/0133738, which is herebyincorporated herein by reference in its entirety.

As the person of skill in the art will appreciate, the wire covering canbe affixed to the roof in a variety of ways. Conventional fasteners suchas nails, staples, adhesives and the like can be used. The wire coveringcan be formed from a material that can be easily nailed through, such asasphalt shingle material. Of course, nailing tabs or zones can also beprovided on the wire covering.

The wiring can be provided in many different ways. For example, it canbe provided as a single wire or cable, or a bundle of wires or cables.In certain embodiments, the wiring (e.g., as wire or cable) is heldwithin a conduit, over which the wire covering is disposed. For example,as shown in schematic cross-sectional view in FIG. 12, wires 1202 areheld within conduit 1242 beneath wire covering 1204 and roofing material1232. Such embodiments can be advantageous, in that code-approvedconduit can be used, ensuring electrical safety and reliability, whileproviding the advantages described herein.

In certain embodiments of the invention, the wire covering includes oneor more wire holding structures on its roof-facing surface. The one ormore wire holding structures can be, for example, one or more wireclips, as shown in FIG. 13 in schematic perspective view of theroof-facing surface of a flexible wire cover 1304. The roof-facingsurface 1344 includes clips 1346 that can hold a wire in place along theroof-facing surface. Of course, the person of skill in the art willappreciate that other wire holding structures can also be used in thepresent invention. For example, in other embodiments of the inventionthe one or more wire holding structures can be one or more sections ofcable holding tray, one or more sections of conduit, or one or morehooks. In other embodiments of the invention, the electrical cable isattached to the roof-facing surface of the wire covering, for examplewith an adhesive, tape, tacks, or staples. A groove or recess can beformed in the roof-facing surface of the wire covering, in which thewire can be disposed. Such wire holding structures can be especiallyhelpful when a separate conduit is not used, and especially when thewire is jacketed wires (i.e., not protected in cable form).

In certain embodiments, the wire covering is disposed substantiallyunderneath another roofing element of the roof. For example, in oneembodiment, the wire and the wire covering are disposed along a courseof roofing elements, and are substantially covered by an overlyingcourse of roofing elements. One such embodiment is shown in schematiccross-sectional view in FIG. 14, and in schematic top view in FIG. 15.Wiring system 1400 includes wire 1402 and wire covering 1404, disposedon roofing elements 1416 of roof 1410. As shown in FIG. 15, roofingelements 1416 are arranged horizontally in a single course along theroof, and the wire 1402 and the wire covering 1404 extend horizontallyalong them. The wire covering is substantially covered by an overlyingcourse of roofing elements 1418. In such embodiments, the wire can bebetter protected from moisture, as described above. Additionally, as thewire covering is covered by a roofing element that is arranged in thepattern of roofing elements, it can be substantially hidden from view.The wire covering described above with reference to FIGS. 5-9, forexample, can advantageously be used in embodiments in which the wirecovering is disposed substantially beneath another roofing element ofthe roof.

In certain embodiments, the wire covering itself is a roofing elementoverlying the roofing element upon which the wire is disposed. Forexample, in one embodiment, the wire is disposed along a course ofroofing elements, and the wire covering is an overlying course ofroofing elements. One such embodiment is shown in schematiccross-sectional view in FIG. 16, and in schematic top view in FIG. 17.Wiring system 1600 includes wire 1602, disposed on roofing elements 1616of roof 1610. As shown in FIG. 17, roofing elements 1616 are arrangedhorizontally in a single course along the roof The wire covering isformed from an overlying course of roofing elements 1618. The wire canbe, for example, disposed within a conduit, as shown by reference number1607 in FIG. 16. The use of NEC-approved conduit can provide protectionto the wire, such that the roofing element is not the only physicalprotection for the wire. Accordingly, use of conduit can be especiallydesirable when the roofing elements are flexible roofing elements, suchas asphalt shingles.

In certain embodiments as described above with respect to FIGS. 15-17,the overlying roofing element is slightly thicker, in order toaccommodate the thickness of the wire and/or wire covering. In certainembodiments, the overly roofing element has a recess formed in itsunderside, in which the wire and/or wire covering can be at leastpartially disposed.

In the embodiments of FIGS. 15-17, the wire covering, the wire, or aconduit in which the wire is disposed can be advantageously attached tothe roof, with the attachment points being concealed and protected fromthe elements by the overlying roofing elements.

Another embodiment of a wiring system according to the present inventionis shown in cross-sectional schematic view in FIG. 18. Several coursesof flexible roofing elements 1816 are shown, disposed on a roof deck1812. Wire coverings 1804 are disposed underneath the down-roof ends1817 of each roofing element, covering a wire 1802 disposed on theroofing element of the next course up the roof, as described above withreference to FIG. 14. Notably, in this embodiment, the wire covering isnot completely covered by the overlying roofing elements; the lateralface 1805 remains exposed as described above with reference to FIG. 8.Other configurations described above with respect to FIG. 8 can likewisebe used in this embodiment.

The wiring systems of the present invention can be used in conjunctionwith a variety of roof-mounted electrical systems. Accordingly, anotheraspect of the invention is a roof-mounted electrical system electricallycoupled to a wiring system as described herein. An electrical system isone which generates or receives an electrical signal or electricalpower. For example, the wiring systems of the present invention can beused in conjunction with (e.g., electrically interconnected with)roof-mounted photovoltaic modules, to interconnect individual modulesand/or to connect them to a larger electrical system (e.g., through aninverter). The wiring systems of the present invention can also be usedto interconnect individual photovoltaic roofing elements, and/or toconnect them to a larger electrical system (e.g., through an inverter).The wiring systems of the present invention can also be used inconjunction with other roof-mounted electrical systems, such aswindmills, evaporative coolers, lights, communications equipment such assatellite dishes, or audio equipment. The wiring systems can be made toaesthetically and mechanically integrate with the electrical systems andany other wiring features, for example at the edge of the roof or at aroof penetration.

The wiring systems described herein can be used in conjunction with thephotovoltaic systems described in U.S. Patent Application Publicationsnos. 2008/0271773, 2008/0271774, 2009/0000221, 2009/0000222,2009/0126782, 2009/0133340, 2009/0133738, 2009/0133740, 2009/0133739,2009/0159118, 2009/0178350, 2009/0194143, 2009/0205270 and 2009/0242015,2010/0146878 and 2010/0242831, and in U.S. Provisional PatentApplications Ser. Nos. 61/220,475, 61/232,739 61/261,638 and 61/291,954,each of which is hereby incorporated herein by reference in its entiretyfor all purposes. The wire coverings described herein can be used tocover wire that is within the systems described therein, andadditionally or alternatively to cover wire that connects the systemsdescribed therein to an electrical system.

The wiring systems as described herein can be used in conjunction withother building elements that conceal wires or cables. For example, asshown in schematic perspective view in FIG. 19, the wiring systems canbe used with a trim strip that covers the wiring, for example, as itruns along the fascia of the roof, as described in more detail in U.S.Patent Application Publication no. 2009/0000657, which is herebyincorporated herein by reference in its entirety. In the photovoltaicroofing system 1970, photovoltaic roofing elements 1972, each includinga photovoltaic element 1974 disposed on a roofing substrate 1976, wiredtogether to form the photovoltaic roofing system. Wires 1902 traverseroofing elements 1914 at the edge of the roof, and run along the fasciaof the roof underneath trip strip 1980. On the roof, wires 1902 aredisposed beneath wire coverings 1904, as described herein.

The wiring systems as described herein can be used in conjunction withthe systems described in U.S. Patent Application Publication no.2010/0242381, which is hereby incorporated herein by reference in itsentirety. For example, FIG. 20 shows an example of a wiring systemaccording to the present invention used in conjunction with aphotovoltaic roofing system as described in the 2010/0242381publication. Photovoltaic roofing system 2070 includes a roof deck 2072,upon which one or more (in this case, three) photovoltaic elements 2074are disposed. The one or more photovoltaic elements (together) have atop edge 2076 facing the upper end of the roof deck; a bottom edge 2078facing the lower end of the roof deck, and two side edges 2080. Thephotovoltaic roofing system also includes a plurality of roofingelements 2014 disposed outside the photovoltaic area, along their sideedges 2080. In this embodiment, the roofing elements are granule-coatedbituminous shingles. Photovoltaic roofing system 2070 also includeslinearly-extending side flashing 2082 disposed along the side edges ofthe contiguously-disposed photovoltaic elements. Wire 2002 connects thephotovoltaic elements 2074 to an electrical system (not shown), and iscovered by a wire covering as described herein. In the embodiment ofFIG. 20, the wire 2002 is disposed on shingles 2016, and the wirecoverings are formed from shingles 2018, as described above withreference to FIGS. 16 and 17.

The photovoltaic system can include a top flashing disposed along thetop edge of the photovoltaic area, as shown in the embodiment of FIG. 20by reference numeral 2084. In certain embodiments, the top flashing caninclude one or more cavities and/or recesses that act as a cover and/orconduit for electrical connectors or cables or other electrical featuresthat protrude from the surface of the photovoltaic elements at their topedges. The end of an example of a top flashing for use with the wiringsystems described herein is shown in schematic perspective view in FIG.21. The top flashing 2084 has a side 2086 that substantially closes offthe volume in which the electrical connectors and/or cables associatedwith the photovoltaic elements. The side 2086 has a hole 2088 formedtherein, through which the wiring can emerge, then be covered by thewire covering, as described above with reference to FIG. 20.

Another embodiment of a photovoltaic system is shown in schematicperspective view in FIG. 22. The wire covering 2204 and roofing elements2216 are configured as described above with reference to FIG. 18. Theroofing elements have photovoltaic elements (e.g., photovoltaiclaminates) 2272 disposed thereon. Wires 2202 connect the photovoltaicelements to one another; each emerges from a photovoltaic element,enters the wire covering through a hole formed therein, and connects toa neighboring wire underneath the wire covering. Of course, otherconfigurations are possible, as the person of skill in the art willrecognize. For example, in other embodiments, wires can emerge from thebottom surface of a roofing element, and enter the wire coveringdisposed beneath the roofing element from its top surface.

Another aspect of the invention is a method for installing a wiringsystem as described herein on a roof comprising one or more roofingelements disposed on a roof deck, as described herein. The methodincludes disposing the wire and the wire covering on the roofingelements such that the wire covering covers the wire. In one embodiment,the wire can be disposed on the roofing elements first, then the wirecovering formed thereon. In another embodiment, the wire and the wirecovering are assembled together, then disposed on the roof.

In one embodiment, the wire covering is formed from one or more anotherroofing elements disposed on the roof, for example as described abovewith reference to FIGS. 16 and 17. In such embodiments, the wire (e.g.,with a conduit surrounding it) can be inserted between the roofingelements on which it is to be disposed and the overlying roofingelements, after the roofing elements are already installed on the roof.For example, the overlying roofing elements can be lifted and peeledback, and the wire pushed underneath them. The method can be used toretrofit an existing roof with a wiring system.

In another embodiment, the wire covering is substantially covered by oneor more another roofing elements disposed on the roof, for example asdescribed above with reference to FIGS. 14 and 15. In such embodiments,the wire and the wire covering can be inserted between the roofingelements on which it is to be disposed and the overlying roofingelements, after the roofing elements are already installed on the roof.For example, the overlying roofing elements can be lifted and peeledback, and the wire and wire covering pushed underneath them. The methodcan be used to retrofit an existing roof with a wiring system.

Certain aspects of the invention can be further as described in U.S.patent application Ser. No. 13/015,104, filed Jan. 27, 2011, which ishereby incorporated herein by reference in its entirety.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionwithout departing from the scope of the invention. Thus, it is intendedthat the present invention cover the modifications and variations ofthis invention provided they come within the scope of the appendedclaims and their equivalents.

1-20. (canceled)
 21. A wiring system on a roof, the roof comprising aroof deck having a pitch, a first plurality of flexible roofing elementsdisposed horizontally on the roof deck, the first plurality of flexibleroofing elements having an up-roof end and a down-roof end; a secondplurality of flexible roofing elements disposed horizontally on the roofdeck, the first plurality of roofing elements having an up-roof end anda down-roof end, the down-roof end of the second plurality of flexibleroofing elements overlapping the up-roof end of the first plurality offlexible roofing elements; and a third plurality of flexible roofingelements disposed horizontally on the roof deck, the first plurality offlexible roofing elements having an up-roof end and a down-roof end, thedown-roof end of the third plurality of flexible roofing elementsoverlapping the up-roof end of the second plurality of flexible roofingelements; the wiring system comprising: one or more wires extendingalong the roof on top of the second plurality of flexible roofingelements; a substantially rigid wire covering disposed over the secondplurality of flexible roofing elements and the one or more wires,covered by the third plurality of flexible roofing elements.
 22. Thewiring system according to claim 21, wherein the wire covering is aconduit.
 23. The wiring system according to claim 21, wherein the wirecovering forms only acute angles with the roof.
 24. The wiring systemaccording to claim 21, wherein the wire covering extends less than about2″ from the surface of the roof, as measured perpendicularly to the roofsurface.
 25. The wiring system according to claim 21, wherein the wirecovering is formed from substantially rigid sheet metal.
 26. The wiringsystem according to claim 21, wherein the wire covering has wire holdingstructures on its roof-facing surface.
 27. The wiring system accordingto claim 21, wherein the wire covering forms no up-facing valleys havingan up-sloping down-roof end.
 28. The wiring system according to claim21, wherein the wire covering is entirely covered by the third roofingelements.
 29. The wiring system according to claim 21, wherein the wirecovering has a top face disposed over the wire and a lateral facedown-roof from the top face, and wherein the third roofing elementssubstantially cover the top face of the wire covering but not thelateral face of the wire covering.
 30. A method for making a wiringsystem according to claim 21, the method comprising inserting the wirecovering and the one or more wires between the second plurality ofroofing elements and the third plurality of roofing elements, after theroofing elements are already installed on the roof.
 31. The methodaccording to claim 1, wherein the inserting comprises lifting andpeeling back the third plurality of roofing elements and pushing thewire covering and the one or more wires underneath them.
 32. A wiringsystem on a roof, the roof comprising a roof deck having a pitch, afirst plurality of flexible roofing elements disposed horizontally onthe roof deck, the first plurality of flexible roofing elements havingan up-roof end and a down-roof end; a second plurality of flexibleroofing elements disposed horizontally on the roof deck, the firstplurality of flexible roofing elements having an up-roof end and adown-roof end, the down-roof end of the second plurality of flexibleroofing elements overlapping the up-roof end of the first plurality offlexible roofing elements; and a third plurality of flexible roofingelements disposed horizontally on the roof deck, the first plurality offlexible roofing elements having an up-roof end and a down-roof end, thedown-roof end of the third plurality of flexible roofing elementsoverlapping the up-roof end of the second plurality of flexible roofingelements; the wiring system comprising: one or more wires extendingalong the roof on top of the second plurality of flexible roofingelements; a substantially rigid wire covering disposed over the one ormore wires on top of the second plurality of flexible roofing elements;and a layer of flexible roofing material disposed on the substantiallyrigid wire covering.
 33. The wiring system according to claim 32,wherein the substantially rigid wire covering forms no up-facing valleyshaving an up-sloping down-roof end.
 34. The wiring system according toclaim 32, wherein the wire covering has a top face disposed over thewire and a lateral face down-roof from the top face, and wherein theflexible roofing material covers the top face of the wire covering butnot the lateral face of the wire covering.
 35. The wiring systemaccording to claim 32, wherein the wire covering is a conduit.
 36. Thewiring system according to claim 32, wherein the wire covering formsonly acute angles with the roof.
 37. The wiring system according toclaim 32, wherein the wire covering extends less than about 2″ from thesurface of the roof, as measured perpendicularly to the roof surface.38. The wiring system according to claim 32, wherein the wire coveringis formed from substantially rigid sheet metal.
 39. The wiring systemaccording to claim 32, wherein the wire covering has wire holdingstructures on its roof-facing surface.
 40. A method for making a wiringsystem according to claim 32, the method comprising disposing the layerof roofing material, the wire covering and the one or more wires on thesecond plurality of roofing elements, after the roofing elements arealready installed on the roof.